My Kenwood radio installed by the previous owner works great on FM but to hear AM I have to stop the engine because the static is so bad. The static is not popping like a bad plug wire but more like a spewing air hose or FM station off frequency. With the engine off AM works great. Help for my '94 5.8 will be appreciated.

 

Most likely cause of this is the fuel pump in the tank. Ford had a RF filter network available to wire into the fuel pump power leads. You might check at your dealer to see if this is still available. Another possible cause is poor grounding of the aftermarket stereo. Check the wiring and make sure it is securely attached to a good ground, like the firewall or the metal bracing under the dash.

 

Thanks. I think I will start with the radio. Now to figure out how to pull it......I guess it takes a special tool.

 

When I pulled my stock radio I just pushed a framing nail, 10D I think, into each of the 4 holes to release the clips. Radio slid right out. I'm pretty sure most aftermarket radios use the same clips, my older Kenwood did.

 

broncobob, When I turn ignition to ACCY the AM radio works great. At ON but no engine running I get the static. Does that rule out a poor ground? I have not made time to pull the radio and check ground yet. Thanks for both of your help.

 

You might consider checking your antenna. If it has been on long enough it may have rusted underneath where it mounts to the fender. Also when you get time to pull the radio follow the antenna to the base. It may just be rotten from age. I say this because depending on your area (relatively flat not many trees) some fm stations will come in because the signal is better and stronger. AM stations on a good day can be kinda lousy. I know my bronco will get about 80% of the fm stations with the antenna unplugged.

 

I've been researching fixes for this myself.

Your problem is most likely to be the fuel pump. There are several methods to fix it. Ford's fix is a $60 kit that requires removing the fuel pump. .

http://www.arrl.org/tis/info/pdf/W1MG.pdf

The other fixes in the following thread cost much less and do not require removing the fuel pump from the tank.

http://www.hamforum.com/viewtopic.php?t=2099&highlight=

 

Thanks Fomhoire for the link. http://www.arrl.org/tis/info/pdf/W1MG.pdf

You may have ruled out the fuel pump for me. Turned the key to accy and set radio on AM. Works fine. Turn key to on and static continues even after fuel pump stops. So may not be fuel pump. Now I scratch and wonder why I get static with nothing running just key on. Next step check radio ground and antenna. I also see Haynes has an antenna resistance test.

 

try the noise capacitor on the side of the coil

 

If you are getting it with the key on but not running you can try pulling fuses while listening and see which one stops it, then read your manual and see what all is on the circuit. Blower motors usually are never off, just on low ?

If you like AM I also suggest putting a ground strap from your hood to the firewall (after you find the big problem) I can help alot.
Also on many Kenwoods you have to pop off the trim and then it takes a flat "key" that goes in between the sides and the radio. Ask a stereo shop they probably have some to use. I have 2 or 3 different ones from Kenwoods I have had.

 

I finally got a day off. One of the techs at Circuit City pulled the radio. It was in really tight and took him about 15 minutes because the fit was so tight. Good ground. He did not know why the AM static is present when key is on and gone at accy. They offer an antenna booster but it would boost the static also. We left the radio pulled forward. He did not charge me anything and I resisted the comment to say "tackle box, want to go fishing?" due to his piercings. He even looked at the connector and told me a rear speaker was not working. After he shoved the wire back in the connector I'm thinking piercings are not all bad. Back at home, using Haynes manual for antenna check I got 0.8 ohms. Anything under 5.0 is good. Ford dealer had never heard of the fuel pump kit. I don't think the problem is worth pulling the tank anyway. Next step is the noise condensor on the coil then ground the antenna per suggestions then fuse pulling. I noticed the cowl metal flops with the antenna when I was reading impedence and wiggling the antenna. Thanks again for all the great help.

 

I apologize for giving you a play by play update. The Ford shop foreman printed fuse diagrams for me today and also , like one of you gurus, suggested to pull fuses one at a time. When the static is gone pull things on that circuit one at a time. I pulled all fuses under the dash with no static reduction. Under the hood looking at the left row of fuses there are small and large ones. The large 20 just past the 30 amp stopped the static. It is feeding the power control module. Replaced it and pulled the closest square to me on far right, the power control relay and the static stopped again. Looking at Haynes page 12-53 wiring digram the power control relay feeds the coil with a RADIO CAPACITOR attached to the wire, which another one of you gurus suggested. The circuit also feeds the ignition control module which in turn feeds the distributor, starter relay, and into the PCM. Back at the power control relay, another wire from it feeds the EGR control sol, thermactor air diverter sol, thermactor air bypass sol, and idle air bypass sol. I think I will gamble throwing a RADIO CAPACITOR at it next.

 

Well, RADIO CAPACITOR was not it. New one from Ford looks like half a domino with a big notch in the edge. Parts man said there have been at lease two part number changes. AM Radio is still full of stactic with key on and is the same with engine running or not. Crystal clear on Accy. I checked resistance from radio case to good ground on the dash and the radio case is grounded. Hmmmmmm............... that's me humming, the AM radio goes keeeeeeeeeeee............ Like an evacuee from Rita said about hurricanes "You just deal with it." He was not of the entiltlement mentality so we had a good visit. One of the control modules in the PCM circuit must be noisy for my radio. I'll guess I'll just have to deal with it and park when I listen to AM ball games.

 

Another option to parking is to find another power source for your radio. Any wire or fuse that is "hot" with the key on will work. Or you can try to go directly to the battery and see if it eliminates your noise. If you decide to go direct remember to use an inline fuse and to turn off your radio when you stop or it will obviously run down your battery.

 

That noise is really annoying and I would hate to see you have to "just deal with it."